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Dual free layer reader head with magnetic seed layer decoupled from shield

a free layer and shield technology, applied in the field of dual free layer tunnel magnetic resistive (tmr) read heads, can solve the problem of large shield spacing

Active Publication Date: 2021-11-09
WESTERN DIGITAL TECH INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present patent relates to magnetic read heads with a dual free layer (DFL) structure. The DFL structure includes a magnetic seed layer, a first free layer, and a second free layer. A non-magnetic spacer layer is disposed between the first shield and the magnetic seed layer to control the coupling between them. The non-magnetic spacer layer is made of a very thin material, such as a few nanometers, which helps to improve the performance of the magnetic read heads. The magnetic read head assembly also includes a second shield and a TMR sensor disposed on the non-magnetic spacer layer. The technical effects of this patent are to improve the performance of magnetic read heads and to provide a more precise control over the coupling between the first shield and the magnetic seed layer.

Problems solved by technology

Read heads typically include an antiferromagnetic (AFM) layer, which results in a fairly large spacing between shields.
One major challenge in a DFL read head is that the RHB provides a strong field.

Method used

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  • Dual free layer reader head with magnetic seed layer decoupled from shield
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  • Dual free layer reader head with magnetic seed layer decoupled from shield

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Embodiment Construction

[0018]In the following, reference is made to embodiments of the disclosure. However, it should be understood that the disclosure is not limited to specific described embodiments. Instead, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement and practice the disclosure. Furthermore, although embodiments of the disclosure may achieve advantages over other possible solutions and / or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the disclosure. Thus, the following aspects, features, embodiments and advantages are merely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s). Likewise, reference to “the disclosure” shall not be construed as a generalization of any inventive subject matter disclosed herein and shall not be considered to be an element or limitation of the ap...

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Abstract

The present disclosure generally relates to magnetic read heads comprising a dual free layer (DFL) structure. The magnetic read head comprises a first shield, a second shield, and a DFL structure disposed between the first and second shields. The DFL structure comprises a magnetic seed layer, a first free layer, and a second free layer. A non-magnetic spacer layer is disposed between and in contact with the first shield and the magnetic seed layer of the DFL structure at a media facing surface. A material and a thickness of the non-magnetic spacer layer is selected to control the coupling between the first shield and the magnetic seed layer of the DFL structure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims benefit of Chinese patent application serial number 202011535194.7, filed Dec. 23, 2020, which is herein incorporated by reference.BACKGROUND OF THE DISCLOSUREField of the Disclosure[0002]Embodiments of the present disclosure generally relate to dual free layer (DFL) tunnel magnetic resistive (TMR) read heads.Description of the Related Art[0003]Read heads typically include an antiferromagnetic (AFM) layer, which results in a fairly large spacing between shields. A read head without an AFM layer can shrink the distance between shields while also eliminating head instabilities that come from thermal fluctuations in AFM grains.[0004]One such read head is a dual free layer (DFL) read head that has a DFL sensor. A DFL read head does not have an AFM layer, but instead has two free layers individually stabilized longitudinally by antiferromagnetically coupled (AFC) soft bias (SB) structures on either side of the sensor be...

Claims

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Application Information

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Patent Type & Authority Patents(United States)
IPC IPC(8): G11B5/39
CPCG11B5/3932G11B5/3909G11B5/3912
Inventor LIU, XIAOYONGLI, JIBAIÃO DE ALBUQUERQUE, GONCALO MARCOSMAURI, DANIELEOKADA, YUKIMASA
Owner WESTERN DIGITAL TECH INC